Switch



April 8, 1947.

E. G. MILLER EVAL SWITCH Filed Aug. 22, 1944 mmmw Lw m

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Patented Apr. 8, 1947 SWITCH Edward G. Miller and Ralph E. Engberg, New York, N. Y., assgnors, by mesne assignments, to Allied Control Company, Inc., New York, N. Y., a corporation of New York 'Application August 22, 1,944, Serial N0. 550,502

1 This invention relates to switches. An object oi' this invention is a switch having provision for operation into open condition with a snap action under the iniluence'oi resilient means and for being positively moved into open condition in the event that the resilient means Fig. 1 is a plan view of a switch embodying the invention;

Fig. 2 is a section on the line 2-2 of Fig. 1 in the open position of the switch;

Fig. 3 is a section on the line 2-2 of Fig. 1 inthe closed position of the switch;

Fig. 4 is a section on the line lI-JI of Fig. 1, and

Fig. 5 is a detail perspective.

Tn a box-like casing IU of suitable insulating material there are arranged two contact units II and I2 respectively, each consisting of a Sylphon bellows having an end xed to the casing and the other end movable toward and away from the fixed end to close or open a pair of contacts contained in the bellows, such a unit being covered by applicants co-pending application, Serial No. 526,377 filed March 14, 1944. A plate I3 of conducting material rests on and is attached to the movable ends of the contact units iI and I2. The plate I3 has its central portion downwardly offset at IB and between the bottom of the portion I4 and the bottom of the casing II) there is interposed an expansion spring I5 which tends to move the member I3 away from the bottom of the casing IIJ.

A member I6 of suitable insulating material is rotatably supported by the shaft I1 and has a part cut away toform a recess I8. The member `IG is provided with an' actuating handle I9 which extends through an aperture 20 in the cover for the casing IIJ. A rod 2| extends through an aperture 22 in the portion I4 and is provided with a head 23 fitting into the recess I8 and pivotally held therein by a stud 24. The head 23 is of larger cross-section than the rod 2| to form an abutment or shoulder 25. A sleeve 26 is slidably mounted on the rod 2I and a spring 21 interposed between the portion I4 and the sleeve 26 biases the latter toward the shoulder 25.

A U-shaped latch member is rotatably supported by the shaft I1 and consists of two side plates 28 mounted on 'the shaft I1 and a cross bar 35 connecting the two side plates 28 which are located between the ends of the member I6 2 Claims. (Cl. 20G-48) the bellows members of the units II and I2.

and the side walls of the casing I0. Each side member 28 or leg of the latch member is formed with two straight intersecting surfaces 29 and 30, the surfaces 29 being approximately vertical and the surfaces 30 -being approximately horizontal. Additional straight surfaces 30a lead downwardly from the left ends of the surfaces 30. The sleeve 26 is provided with a pair of integral extensions 3 I on each of which is mounted a roller 32 adapted for engagement with the surfaces 29, 30 and 30a in diiferent positions of the switch. A leaf spring 33 tends to rotate the latch member '28 counterclockwise and the extent oi such rotation of the latch member is limited by a stoo 34. One lend of the spring 33 engages the cross bar 35 of the y latch member 28 while the other end is i'lxed to a stationary bracket 36. A pin 31 extends through the lower end of the rod 2| below the bottom surface of the offset portion I 4.

Fig. 2 discloses the switch in open position in which condition the handle I9 is in its leftmost position and the latch 28 is in its extreme position of counterclockwise movement and the rollers 32 engage the surfaces 29, while the member I3 is in its raised position. Clockwise movement of the handle I 9 and member I6 causes initial downward movement of the rod 2| followed by a slight upward movement. The rollers 32 by enga-gement with the surfaces 29 cause clockwise movement of the latch 28 until the rollers clear the ends of the surfaces 29 and move onto the surfaces 30 whereupon the spring 33 brings the surfaces 30a into contact with the rollers 32. Downward movement of the pin 2| compresses the spring 21 causing the latter to force downwardly the member I3 to close the contact units II and I2 respectively, the force of the spring 21 overcoming the upward push of the spring I5 and By engagement of the rollers 32 with the surfaces 30, the spring 21 is maintained under compression to keep the member I3 in contact-closing position, as shown in Fig. 3.

Upon counterclockwise movement of the lever I9 and member I6 from the position shown in Fig. 3, the bar 2| is returned to its original position and the latch member 28 moves counterclockwise under the `influence of the spring 33 to keep the surfaces 3D and 30a engaged with the rollers 32 and thus maintain the spring 21 under contactlosing compression until the handle I9 has nearly completed its return travel during which period the shoulder 25 has been moved out of engagement with the sleeve 2B. At such time, the latch member engages the stop 3 34 whereupon the rollers 32 travel along the surfaces 30 and upon reaching the end thereof they,

together with the sleeve 26, are released for up- Y ward movement under the influence of the spring 21 thereby reducing the pressure exerted by the spring 21 on the plate I3 and allowing it to be moved upwardly with a snap action to open the Contact units H and I2. In the event that the plate i3 does not automatically move upwardly into contact-open position, it is positively pulled upwardly into contact-open position by engagement of the pin 31 with the offset portion I4.

We claim:

`1. In a switch, a contact operator supported for rectilinear movement between two positions, resilient means biasing said contact operator toward one of said positions, an oscillatable member, a rod pivoted at one end to said member and having sliding engagement with said operator, said rod being caused to move bodily relative to said contact operator upon operation of said oscillatablevrnember, a latch pivotally supported coaxial with said osclllatable member and having two intersecting straight surfaces, a

stop to limit rotation of said latch in one direction, resilient means biasing said latch towardi said stop, a sleeve slidable on said rod, an extension from said sleeve engageable with said surfaces and movable from engagement with one surface to engagement with the other surface REFERENCES CITED The following references are of record in the ille of this patent:

UNITED STATES PATENTS Number Name Date 875,030 WOOd Dec. 31, 1907 Piau: Mar. 29, 1898 

